/*
 * Copyright (c) 2000 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.
 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
 */

package org.w3c.dom;

/**
 * This interface represents an entity, either parsed or unparsed, in an XML
 * document. Note that this models the entity itself not the entity declaration.
 * <code>Entity</code> declaration modeling has been left for a later Level of
 * the DOM specification. <p>The <code>nodeName</code> attribute that is
 * inherited from <code>Node</code> contains the name of the entity. <p>An
 * XML processor may choose to completely expand entities before the structure
 * model is passed to the DOM; in this case there will be no
 * <code>EntityReference</code> nodes in the document tree. <p>XML does not
 * mandate that a non-validating XML processor read and process entity
 * declarations made in the external subset or declared in external parameter
 * entities. This means that parsed entities declared in the external subset
 * need not be expanded by some classes of applications, and that the
 * replacement value of the entity may not be available. When the replacement
 * value is available, the corresponding <code>Entity</code> node's child list
 * represents the structure of that replacement text. Otherwise, the child list
 * is empty. <p>The DOM Level 2 does not support editing <code>Entity</code>
 * nodes; if a user wants to make changes to the contents of an
 * <code>Entity</code>, every related <code>EntityReference</code> node has
 * to be replaced in the structure model by a clone of the <code>Entity</code>'s
 * contents, and then the desired changes must be made to each of those clones
 * instead. <code>Entity</code> nodes and all their descendants are readonly.
 * <p>An <code>Entity</code> node does not have any parent.If the entity
 * contains an unbound namespace prefix, the <code>namespaceURI</code> of the
 * corresponding node in the <code>Entity</code> node subtree is
 * <code>null</code>. The same is true for <code>EntityReference</code>
 * nodes that refer to this entity, when they are created using the
 * <code>createEntityReference</code> method of the <code>Document</code>
 * interface. The DOM Level 2 does not support any mechanism to resolve
 * namespace prefixes. <p>See also the <a
 * href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113'>Document
 * Object Model (DOM) Level 2 Core Specification</a>.
 */
public interface Entity extends Node
{
   /**
    * The public identifier associated with the entity, if specified. If the
    * public identifier was not specified, this is <code>null</code>.
    */
   public String getPublicId();

   /**
    * The system identifier associated with the entity, if specified. If the
    * system identifier was not specified, this is <code>null</code>.
    */
   public String getSystemId();

   /**
    * For unparsed entities, the name of the notation for the entity. For parsed
    * entities, this is <code>null</code>.
    */
   public String getNotationName();

}
